1. Technical Field
Embodiments of the present disclosure relate generally to amplifiers, and more specifically to measuring load impedance of an amplifier driving a variable load.
2. Related Art
An amplifier is a circuit and/or a component, which amplifies an input signal, and provides the amplified signal at a corresponding output node. Circuits or components connected to an output node on which the amplified output is provided are termed as a load. A load may be associated with a corresponding impedance, which may contain both a resistive part (character of a resistor) as well as a reactive part (character of a capacitance/inductance).
In several scenarios, the impedance of a load presented to an amplifier varies with time. For example, the load impedance presented by an antenna to a power amplifier may vary (the resistive part or the reactive part or both) due to changes in the environment of antenna operation (for example, depending on the nature and location of objects in the vicinity of the antenna).
In other scenarios, circuit structures or components constituting the load may be replaced by a different circuit or component by a user or systems integrator, thereby causing the load to the amplifier to be changed (from a value that the amplifier was originally designed to operate with).
Measurement of the value of a load impedance connected to an amplifier is often desirable. The measured value can be used, for example, to ensure maximum power transfer to the load and to reduce damages to the output stages of the amplifier. It may accordingly be desirable to measure the load impedance of an amplifier driving a variable load.